Laser-heated needle for biopsy tract ablation: In vivo study of rabbit liver biopsy.

Abstract

To investigate the efficacy of a newly-developed laser-heated core biopsy needle in the thermal ablation of biopsy tract to reduce hemorrhage after biopsy using in vivo rabbit's liver model. Five male New Zealand White rabbits weighed between 1.5 and 4.0kg were anesthetized and their livers were exposed. 18 liver biopsies were performed under control group (without tract ablation, n=9) and study group (with tract ablation, n=9) settings. The needle insertion depth (~3cm) and rate of retraction (~3mm/s) were fixed in all the experiments. For tract ablation, three different needle temperatures (100, 120 and 150°C) were compared. The blood loss at each biopsy site was measured by weighing the gauze pads before and after blood absorption. The rabbits were euthanized immediately and the liver specimens were stained with hematoxylin-eosin (H&E) for further histopathological examination (HPE). The average blood loss in the study group was reduced significantly (p<0.05) compared to the control group. The highest percentage of bleeding reduction was observed at the needle temperature of 150°C (93.8%), followed by 120°C (85.8%) and 100°C (84.2%). The HPE results show that the laser-heated core biopsy needle was able to cause lateral coagulative necrosis up to 14mm diameter along the ablation tract. The laser-heated core biopsy needle reduced hemorrhage up to 93.8% and induced homogenous coagulative necrosis along the ablation tract in the rabbits' livers. This could potentially reduce the risk of tumor seeding in clinical settings.